package com.zjz.CoAndSE_DEMO;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;

public class CookieDemo01 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //服务器告诉你：你来的时间，把这个时间封装成一个信件，你下次带来，我就知道你来了

        //解决中午乱码
        req.setCharacterEncoding("utf-8");
        resp.setCharacterEncoding("utf-8");

        PrintWriter out = resp.getWriter();

        //Cookie,服务端从客户端获取：
        Cookie[] cookies = req.getCookies();  //这里返回数组，说明Cookie可能存在多个

        //判断Cookie是否存在
        if(cookies != null){
            //如果存在怎么办、
            out.write("你上一次访问的时间为：");

            for(int i = 0; i < cookies.length; i++){
                Cookie cookie = cookies[i];
                //获取cookie的名字
                if(cookie.getName().equals("firstName")){
                    //获取cookie中的值
                    String value = cookie.getValue();
                    long firstName = Long.parseLong(value);
                    Date date = new Date(firstName);
                    out.write(date.toLocaleString());
                }
            }
        }else {
            out.write("这是您第一次访问本站！");
        }
        //服务器给客户端响应一个Cookie
        Cookie cookie = new Cookie("firstName", System.currentTimeMillis()+"");
        resp.addCookie(cookie);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

    }
}
